Cac cau hoi phong van .NET thuc te kem cau tra loi, dau hieu canh bao va cau hoi truy van tiep theo. Noi dung bao gom C#, EF Core, ASP.NET Core va thiet ke he thong, cap nhat cho .NET 10 va C# 14.
Phong van .NET nam 2026 chu yeu tap trung vao tinh huong, khong con chi hoi dinh nghia. Nha tuyen dung tot se khong chi hoi “dependency injection la gi?”, ma se hoi: “Ban da tiem mot scoped service vao singleton. Ung dung chay binh thuong trong moi truong phat trien nhung lam sai lech du lieu trong san pham. Chuyen gi da xay ra?”.
Bai viet nay tong hop nhung cau hoi lien nganh quan trong nhat, kem cach tra loi nen dung, cau tra loi de bi tru diem va cau hoi tiep theo ma nguoi phong van co the dat ra. Noi dung duoc cap nhat cho .NET 10 va C# 14.
Mục lục
Phong van .NET nam 2026 dien ra nhu the nao?
Truoc khi hoc tung cau hoi, ban can hieu cau truc cua buoi phong van. Phan nay cho biet moi vong dang kiem tra dieu gi va ban nen chuan bi ra sao. Tai nhieu cong ty san pham, phong van .NET gom bon vong:
- Vong sang loc va nen tang: Cac chu de gom kien thuc C#, kieu gia tri va kieu tham chieu, async/await va LINQ. Vong nay loai nhung ung vien chua the lap trinh vung. Cac cau hoi dinh nghia van co the xuat hien, nhung cac nha phong van tot thuong dua vao tinh huong.
- Vong chuyen sau ve ky thuat: Tap trung vao noi bo ASP.NET Core, EF Core va cac framework ban se su dung hang ngay. Cau hoi tinh huong chiem uu the va day la vong quyet dinh phan lon ket qua.
- Vong thiet ke he thong: Vi du: “Hay thiet ke mot rate limiter” hoac “Hay thiet ke mot dich vu thong bao”. Vong nay kiem tra kha nang suy luan ve quy mo, danh doi va loi, dac biet quan trong voi vi tri mid va senior.
- Vong hanh vi va phan doan: Vi du: “Hay ke ve mot su co trong san pham” hoac “Khi nao ban tung phan bien mot quyet dinh ky thuat?”. Vong nay danh gia tinh chu dong, trach nhiem va kha nang giao tiep.
Diem khac biet cua ung vien manh la ho khong hoc thuoc long. Ho bat dau bang lua chon mac dinh, neu ro danh doi va giai thich khi nao se chon phuong an khac. Do cung la ky nang ma cac cau hoi ben duoi muon ren luyen.
Cum cau hoi phong van .NET
Danh sach duoi day gom nhung chu de xuat hien thuong xuyen nhat. Neu muon hoc sau hon, ban co the mo rong theo tung nhom:
- C#: record, kieu gia tri, pattern matching va generic.
- ASP.NET Core: middleware, vong doi DI, hosting, cau hinh va options.
- Thiet ke he thong: rate limiter, hang doi, idempotency va kha nang mo rong.
- Async va da luong: async/await, Task, thread pool va deadlock.
- LINQ: thuc thi tri hoan, IEnumerable, IQueryable, expression tree va cac toan tu.
- Microservices: ranh gioi dich vu, messaging, resilience va saga.
- Cap do senior: phan doan ve kien truc, danh doi va lanh dao ky thuat.
- SQL Server: index, query plan, transaction va locking.
- Docker va DevOps: container, CI/CD, trien khai va pipeline.
Doc cau hoi moi la buoc dau tien. De biet ban co the nho va van dung duoc duoi ap luc hay khong, hay tu gioi han thoi gian va tu tra loi truoc khi xem dap an.
Cau hoi ve ngon ngu C#
Cau 1: Record khac class nhu the nao va khi nao nen dung record?
record la mot kieu tham chieu tuong tu class, nhung trinh bien dich cung cap san phep so sanh theo gia tri, ham ToString va kha nang sao chep bang bieu thuc with. Hai record co cung gia tri thuoc tinh se duoc xem la bang nhau; hai doi tuong class se khong bang nhau neu ban khong tu ghi de Equals.
Toi thuong dung record khi kieu du lieu duoc xac dinh boi du lieu ben trong va gan nhu bat bien, vi du DTO, mo hinh request/response cua API, value object va event. Toi dung class khi doi tuong co danh tinh rieng va hanh vi co the thay doi, vi du entity cua EF Core hoac service.
Cau tra loi can tranh: “Record chi la cach viet ngan hon cua class.” Cau tra loi nay bo qua co che so sanh theo gia tri, von la diem cot loi cua record.
Cau 2: Dieu gi xay ra khi boxing mot kieu gia tri va tai sao dieu do quan trong?
Boxing dat mot kieu gia tri, vi du int hoac struct, vao mot doi tuong tren heap de no co the duoc su dung nhu kieu tham chieu. Qua trinh nay tao allocation; khi unboxing, gia tri duoc sao chep ra ngoai. Trong vong lap nong, boxing lap di lap lai tao ap luc cho bo thu gom rac va co the gay tang do tre.
Boxing xuat hien nhieu hon ban nghi: luu struct vao collection khong generic, truyen struct vao noi cho doi hoi object hoac interface, hay chen kieu gia tri vao chuoi. Trong API co thong luong cao, day la nguon allocation am tham. Generic va Span<T> thuong giup tranh van de nay.
Cau tra loi can tranh: “Boxing khong quan trong, bo thu gom rac se xu ly.” Nhan dinh nay chi dung cho den khi ban profile duong chay nong va thay boxing chiem phan lon allocation.
Cau 3: Ban thay async void trong code review. Tai sao can danh dau?
async void la mot ham chay khong dong bo ma ben goi khong the await. Ben goi khong biet khi nao ham ket thuc va cung khong co cach truc tiep phat hien loi. Nghiem trong hon, exception trong ham async void khong duoc dong goi trong mot task tra ve; no duoc dua len synchronization context va co the lam ung dung dung hoat dong.
Truong hop hop le duy nhat thuong la event handler. Cac truong hop khac nen dung async Task. Khi thay async void ngoai event handler, toi cho rang co nguy co exception khong duoc quan sat lam sap ung dung.
Cau tra loi can tranh: “No van chay binh thuong.” No chi chay binh thuong cho den khi phat sinh exception ma khong co noi nao bat duoc.
Cau hoi tiep theo: “Khi nao async void thuc su la lua chon dung?”
Cau hoi ve async va da luong
Cau 4: Dieu gi thuc su xay ra khi goi .Result hoac .Wait() tren Task?
Ban khoa luong hien tai cho den khi task hoan tat, lam mat loi ich cot loi cua lap trinh khong dong bo. Trong duong xu ly request, hau qua con nang hon: khi tai tang, cac thread trong thread pool bi giu lai de cho I/O, pool bi can kiet va thong luong giam manh du CPU van dang ranh.
Hien tuong nay goi la thread-pool starvation. API co the nhanh khi tai nhe nhung sap do khi co luu luong thuc te.
Quy tac cua toi la async tu dau den cuoi. Neu mot phuong thuc goi ham async, no nen tra ve task va duoc ben goi await. Khong nen dung .Result de noi cau truc dong bo voi cau truc khong dong bo.
Cau tra loi can tranh: “Toi dung .Result khi khong muon doi phuong thuc thanh async.” Day la cach tao ra API chet khi he thong mo rong.
Cau 5: Task khac Thread nhu the nao?
Thread la luong cap he dieu hanh, nang, ton nhieu tai nguyen va ton chi phi khoi tao. Task la lop truu tuong cap cao dai dien cho mot cong viec. Cong viec co the chay tren thread pool, hoan tat bat dong bo trong qua trinh cho I/O ma khong giu mot thread, hoac chay truc tiep.
Trong .NET hien dai, ban gan nhu khong can tu tao Thread. Hay dung Task cung async/await va de runtime lap lich. Diem quan trong: Task khong phai la thread. Khi cho I/O, task co the tra thread ve pool; do la ly do async co kha nang mo rong tot hon.
Cau tra loi can tranh: “Task va Thread la mot, Task chi la thread viet ngan hon.” Neu tra loi nhu vay, ban se khong the giai thich tai sao I/O khong dong bo mo rong tot hon viec tao them thread.
Cau hoi ve LINQ
Cau 6: Truy van LINQ thuc su chay khi nao?
LINQ su dung deferred execution, tuc la thuc thi tri hoan. Viec xay dung truy van voi Where, Select hoac OrderBy khong lap tuc chay truy van; no chi tao ra mo ta cong viec. Truy van chi chay khi ban duyet ket qua bang ToList, ToArray, Count, First hoac foreach.
Dieu nay quan trong vi voi EF Core, thuc thi tri hoan cho phep provider dich ca chuoi thao tac thanh mot cau lenh SQL. Tuy nhien, neu ban duyet cung mot truy van hai lan, no co the chay hai lan va truy cap co so du lieu hai lan. Khi can dung ket qua nhieu lan, hay materialize bang ToList truoc.
Cau tra loi can tranh: “Truy van chay ngay khi viet Where.” Nhan dinh nay khong giai thich duoc vi sao cung mot truy van co the goi co so du lieu nhieu lan.
Cau hoi ve ASP.NET Core
Cau 7: Thu tu middleware dung cho routing, CORS, authentication va authorization la gi?
Thu tu middleware khong phai chi de trang tri. Moi middleware phu thuoc vao nhung middleware chay truoc no. Trinh tu thong thuong la:
UseRouting → UseCors → UseAuthentication → UseAuthorization → endpoint.
Authentication phai chay truoc authorization vi he thong can biet nguoi dung la ai truoc khi kiem tra ho duoc phep lam gi. CORS can nam truoc authentication de cac request preflight nhan duoc header can thiet.
Loi kinh dien la dang ky CORS hoac authentication sai vi tri, sau do gap 401 am tham hoac thieu CORS header. Nhieu loi trong so nay bi nham la loi cua framework, nhung thuc ra la loi thu tu pipeline.
Cau tra loi can tranh: “Thu tu khong quan trong, ASP.NET Core tu tu xu ly.” Thu tu thuc su rat quan trong va day la bay phong van pho bien.
Cau 8: Dieu gi xay ra khi tiem scoped service vao singleton?
Day la hien tuong captive dependency. Singleton duoc tao mot lan va ton tai trong suot vong doi ung dung, vi vay no giu lai cung mot scoped service mai mai, trong khi scoped service dang le phai duoc tao theo moi scope, thuong la moi request.
Voi DbContext, hau qua co the la mot context bi dung chung giua cac request, vi pham an toan luong, du lieu cu va change tracker phinh to khong gioi han.
Khi bat scope validation, container DI cua .NET co the phat hien loi nay luc khoi dong. Cach sua pho bien la tiem IServiceScopeFactory vao singleton va tao scope moi cho tung don vi cong viec.
Cau tra loi can tranh: “Khong co gi, no van chay.” No co the chay trong demo nhung lam hong du lieu khi co dong thoi.
Cau hoi tiep theo: “Container mac dinh phat hien loi nay bang cach nao va khi nao no khong phat hien duoc?”
Cau hoi ve EF Core
Cau 9: Endpoint tra ve 50 dong nhung log cho thay 51 query. Chuyen gi da xay ra?
Day la van de N+1 query: mot query tai 50 dong cha, sau do EF Core chay them mot query cho moi dong de tai navigation property lien quan. Ket qua la 50 round trip du thua.
Nguyen nhan thuong den tu lazy loading hoac viec duyet navigation property ma ban quen dung Include. Cach sua la eager loading bang Include, hoac tot hon la chi chieu ra cac truong can thiet bang Select de tao mot query duy nhat va tranh tai thua du lieu.
Hay bat query logging cua EF Core trong moi truong phat trien. Mot loat query giong nhau lap lai se lo ra rat nhanh.
Cau tra loi can tranh: “Toi se tang kich thuoc connection pool.” Cach nay chi phong dai trieu chung, khong sua nguyen nhan.
Cau 10: Khi nao dung AsNoTracking va diem danh doi la gi?
AsNoTracking bo qua viec tao snapshot de theo doi thay doi, giup tiet kiem bo nho va CPU trong cac truy van chi doc. Toi dung no cho cac truy van kieu GET ma ket qua khong can chinh sua.
Diem can luu y la khi khong tracking, EF Core mac dinh khong thuc hien identity resolution. Cung mot dong xuat hien hai lan trong join co the duoc materialize thanh hai doi tuong rieng. Ngoai ra, ban khong the goi SaveChanges cho entity chua duoc theo doi theo cach thong thuong.
Cau tra loi can tranh: “Toi dat AsNoTracking cho moi truy van vi no nhanh hon.” Neu vay, cac thao tac cap nhat cua ban se hoat dong the nao?
Cau hoi thiet ke he thong
Cau 11: Hay thiet ke rate limiter cho API da tenant
Truoc tien, toi se lam ro gioi han ap dung theo tenant, user hay API key, dong thoi xac dinh cac goi dich vu va quota. Sau do chon thuat toan: token bucket cho burst muot hon, fixed window hoac sliding window cho quota don gian, va phan chia bo gioi han theo tenant identifier.
Diem quan trong la rate limiter trong bo nho khong hoat dong dung khi ung dung co nhieu instance. Moi replica se tu ap dung gioi han rieng; ba instance co the cho phep xap xi gap ba lan toc do mong muon. Trong he thong phan tan, counter can nam trong kho dung chung nhu Redis.
API nen tra ve 429 kem header Retry-After de client biet khi nao co the thu lai.
Cau tra loi can tranh: “Toi dung middleware rate limiter co san la xong.” Cach nay co the du cho mot instance, nhung co the lam hong gioi han khi scale out.
Cau hoi tiep theo: “Neu Redis ngung hoat dong, ban se fail open hay fail closed?”
Cau 12: Bo xu ly background job dang cham 2 trieu message. Ban lam gi?
Truoc tien, can tach van de tuc thoi khoi nguyen nhan goc. Hay kiem tra consumer da du suc xu ly hay chua, cong viec dang bi gioi han boi CPU, I/O, lock hay mot partition duy nhat. Backlog lon nhieu khi do mot dependency phia sau cham, khong phai do thieu may chu.
Ve cau truc, hay lam cho viec xu ly message co tinh idempotent de co the xu ly lai an toan, batch neu he thong phia sau cho phep, va them dead-letter queue de message loi khong chan ca hang doi.
Cau tra loi can tranh: “Toi chi can them consumer.” Neu co so du lieu phia sau la nut that, them consumer se lam tinh hinh te hon.
Cau 13: Lam the nao de endpoint thanh toan co tinh idempotent?
Idempotency co nghia la cung mot request duoc ap dung hai lan phai cho cung tac dong nhu ap dung mot lan. Dieu nay dac biet quan trong voi thanh toan, vi client co the thu lai va khong duoc bi tru tien hai lan.
Client gui mot idempotency key, thuong la GUID, cung request. Server luu key kem ket qua. Neu cung key xuat hien lan nua, server tra ve ket qua da luu thay vi xu ly lai.
Chi tiet phan biet cau tra loi manh la key phai duoc luu mot cach nguyen tu cung voi giao dich tru tien, trong cung transaction. Neu he thong bi dung sau khi tru tien nhung truoc khi luu key, cua so gay tru tien hai lan van con ton tai.
Cau tra loi can tranh: “Toi se kiem tra xem giao dich da ton tai truoc khi insert.” Kieu check-then-act co the gap race condition khi co nhieu request thu lai dong thoi.
Cau hoi ve kien truc va phan doan
Cau 14: Khi nao khong nen dung microservices?
Trong phan lon truong hop, cau tra loi la: khi doi nhom va bai toan chua can den no. Microservices giai quyet van de ve to chuc va kha nang mo rong, chu khong tu dong giai quyet van de chat luong code.
Neu nhom nho, domain con thay doi, khong co nhu cau scale doc lap va nang luc DevOps con han che, microservices se them chi phi cua he thong phan tan: loi mang, eventual consistency, quan sat he thong phuc tap va van de giao dich lien dich vu.
Lua chon mac dinh cua toi la modular monolith: chia module ro rang trong mot ung dung co the trien khai cung nhau. Chi tach thanh service khi mot ap luc cu the, co ten ro rang, bat buoc phai tach.
Cau tra loi can tranh: “Microservices la cach hien dai nen luc nao cung nen dung.” Day la thiet ke theo xu huong thay vi theo bai toan.
Cau 15: CQRS co dang gia khong va khi nao nen dua vao?
CQRS tach mo hinh doc khoi mo hinh ghi. No phat huy hieu qua khi hai phia thuc su co hinh dang hoac nhu cau scale khac nhau, vi du domain ghi phuc tap co nhieu invariant nhung he thong doc co luu luong cao va can projection da chuan hoa hoac cache.
CQRS khong mien phi. No them nhieu thanh phan va thuong tao ra eventual consistency giua phia doc va phia ghi. Toi khong dua CQRS vao mot service CRUD don gian. Toi chi dung no khi duong doc va duong ghi bat dau can tro nhau.
Cau tra loi can tranh: “Toi luon dung CQRS cung mediator vi do la clean architecture.” Them lop trung gian vao CRUD khong lam kien truc sach hon; no co the chi tao them chi phi.
Cau hoi ve hieu nang va caching
Cau 16: Hai tram request cung gap mot cache key rong va cung truy cap co so du lieu. Day la gi va xu ly ra sao?
Day la cache stampede, con goi la thundering herd. Mot key pho bien het han, sau do moi request dong thoi cache miss va cung tinh lai gia tri tu co so du lieu. Tai tang dung luc cache dang le phai bao ve he thong.
Trong .NET 10, co the dung HybridCache voi co che bao ve stampede co san. Nhieu request cung cho mot key thieu se doi mot phep tinh duy nhat thay vi cung danh vao nguon du lieu. Truoc khi co HybridCache, ban co the tu cai dat lock theo tung key tren duong xu ly cache miss.
Cau tra loi can tranh: “Toi chi can dat thoi gian het han dai hon.” Cach nay chi lam stampede it xay ra hon, khong loai bo no, dong thoi lam du lieu cu hon.
Cau hoi ve testing va van hanh san pham
Cau 17: Lam the nao integration test API ket noi toi co so du lieu that?
Toi dung WebApplicationFactory de khoi dong ung dung voi pipeline that trong bo nho, sau do ket noi den co so du lieu that chay trong container thong qua Testcontainers. Khong nen chi dung provider in-memory cua EF Core, vi no khong mo phong dung hanh vi SQL that nhu constraint, transaction va concurrency token.
Cach ket hop nay cho phep test chay qua pipeline request thuc te va database engine thuc te, dong thoi container duoc tao va huy theo moi lan chay test. Do la muc do tin cay ma unit test don thuan khong the cung cap.
Cau tra loi can tranh: “Toi dung EF Core in-memory provider cho integration test.” Test co the pass trong moi truong gia lap nhung fail khi len san pham.
Cau 18: Xu ly graceful shutdown cho API .NET chay tren Kubernetes nhu the nao?
Khi orchestrator gui SIGTERM, ung dung nen ngung nhan request moi, hoan tat request dang chay trong thoi han cho phep va giai phong tai nguyen. ASP.NET Core ho tro co che nay thong qua IHostApplicationLifetime va shutdown timeout.
Voi cong viec nen, stoppingToken truyen vao BackgroundService la tin hieu de cong viec dung lai sach se.
Chi tiet the hien kinh nghiem van hanh la readiness probe phai chuyen sang trang thai khong san sang truoc khi shutdown de load balancer ngung gui traffic. Shutdown timeout cung can dai hon request hop ly lau nhat; neu khong, request dang chay co the bi giet giua chung.
Cau tra loi can tranh: “Kubernetes chi can giet va khoi dong lai pod.” Cach nay co the lam mat request dang xu ly va lam hong cong viec chua checkpoint.
Cau hoi ve Web API
Cau 19: POST tao resource va kich hoat background job bat dong bo. Nen tra ve status code nao?
Dieu nay phu thuoc vao trang thai thuc te tai thoi diem tra response. Neu resource da duoc tao dong bo va job chi la side effect, hay tra ve 201 Created kem header Location tro den resource moi.
Neu toan bo operation duoc dua vao hang doi va chua hoan tat, hay tra ve 202 Accepted kem URL de client kiem tra trang thai. 200 OK khong phai lua chon tot trong truong hop nay vi khong truyen tai day du y nghia cua thao tac tao moi.
Cau tra loi can tranh: “200 vi request da thanh cong.” Voi endpoint tao resource, cau tra loi nay bo qua thong tin ma status code duoc tao ra de bieu dat.
Cau 20: PUT khac PATCH nhu the nao va nen mac dinh dung cai nao?
PUT thay the toan bo resource; client gui bieu dien day du cua resource. PATCH cap nhat mot phan; client chi gui nhung truong thay doi.
PATCH nghe co ve linh hoat hon nhung them nhieu phuc tap. He thong phai phan biet truong bi bo qua voi truong duoc dat gia tri null, dong thoi cach truyen JSON Patch co the kho dung voi mot so client.
Voi nhieu API noi bo, toi mac dinh dung PUT cung doi tuong day du vi no don gian va it loi hon. Toi chi chon PATCH khi entity lon, bang thong la van de dang ke hoac cap nhat tung phan la yeu cau thuc su.
Cau tra loi can tranh: “PUT va PATCH co the dung thay cho nhau.” Hai phuong thuc co y nghia khac nhau; nham lan se tao ra API kho doan.
5 sai lam khien lap trinh vien .NET bi tu choi
- Doc lai dinh nghia thay vi suy luan: Noi “middleware la phan mem nam giua request va response” khong cho thay kinh nghiem. Tot hon la ke ve mot lan dang ky CORS sai thu tu va gap 401 gia trong san pham.
- Chi noi “tuy truong hop” roi dung lai: Cau tra loi senior co the bat dau bang “tuy truong hop”, nhung ngay sau do phai neu lua chon mac dinh, danh doi va dieu kien de chon phuong an khac.
- Mac ket o phien ban cu: Neu phong van nam 2026 ma ban chi nhac den cac mau cu hoac hanh vi cu, nguoi phong van co the nghi rang ban da ngung cap nhat kien thuc. Hay nam ro nhung thay doi trong .NET 10 va C# 14.
- Khong co dau hieu tu san pham: Nguoi phong van muon nghe cac cau nhu “Toi tung gap loi nay khi…”, “He thong cua chung toi da co su co…” hoac “Toi da benchmark viec nay”. Cau tra loi hoan toan ly thuyet se yeu hon cau tra loi co kinh nghiem thuc te.
- Bo qua ly do: “Toi se dung output caching” chi la cau tra loi trung binh. “Toi dung output caching vi no ho tro invalidation theo tag, cho phep xoa cache ngay khi ghi thay vi doi TTL” moi the hien muc do hieu sau.
Dieu can ghi nho
- Tinh huong quan trong hon dinh nghia: Hay luyen tra loi “ban se lam gi khi…” thay vi chi hoc “… la gi?”.
- Cau tra loi manh luon ket thuc bang danh doi: Neu lua chon mac dinh, chi phi cua no va khi nao ban se thay doi lua chon.
- Nhan dien cac dau hieu canh bao: Neu sap noi “toi se dung
.Result”, “luc nao cung dung microservices” hoac “tao moi thi tra 200 OK”, hay dung lai va suy nghi sau hon. - Cap nhat .NET 10 va C# 14: HybridCache, named query filters, ExecuteUpdate, primary constructors, records va collection expressions la nhung chu de co the xuat hien trong phong van hien dai.
- Cau hoi truy van tiep theo moi la noi phan thang bai: Khong chi chuan bi cau tra loi dau tien; hay chuan bi ca cau hoi cap do hai ma nguoi phong van co the dat tiep.
Cau hoi thuong gap
Phong van .NET nam 2026 thuong hoi nhung gi?
Phong van hien dai tap trung vao tinh huong thay vi dinh nghia. Cac chu de thuong gap gom tinh nang C#, async va da luong, LINQ, noi bo ASP.NET Core nhu thu tu middleware va vong doi dependency injection, truy cap du lieu bang EF Core, thiet ke he thong va cac quyet dinh kien truc. Muc tieu la xem ban co tung xay dung va go loi ung dung thuc te hay chua.
Chuan bi phong van lap trinh vien .NET nhu the nao?
Hay chuan bi theo tung vong. Vong sang loc kiem tra nen tang C# va async. Vong ky thuat di sau vao ASP.NET Core va EF Core. Vong thiet ke he thong kiem tra kha nang suy luan ve quy mo va danh doi. Vong hanh vi danh gia tinh chu dong va trach nhiem. Voi moi chu de, hay luyen tra loi theo cau truc: lua chon mac dinh, danh doi va khi nao se chon cach khac.
Phong van .NET co bao nhieu vong?
Nhieu cong ty san pham co bon vong: sang loc hoac nen tang, ky thuat chuyen sau, thiet ke he thong va hanh vi hoac phan doan. Cong ty nho co the gop thanh mot hoac hai buoi, trong khi cong ty lon co the them vong lap trinh va kien truc.
Lap trinh vien .NET senior can biet gi?
Ung vien senior can biet suy luan ve danh doi thay vi chi nho kien thuc. Ban can giai thich khi nao dung hoac khong dung mot mau thiet ke, chan doan thread-pool starvation, N+1 query va cache stampede, thiet ke rate limiter, tao payment API idempotent va quyet dinh giua modular monolith voi microservices.
Cau hoi .NET co khac nhau giua ung vien it kinh nghiem va nguoi da co kinh nghiem?
Co. Ung vien junior thuong duoc hoi ve nen tang ngon ngu va kha nang lap trinh. Ung vien co kinh nghiem se gap nhieu cau hoi ve tinh huong, go loi san pham, thiet ke he thong va phan doan kien truc. Cung mot chu de co the xuat hien o moi cap do nhung muc do kho tang dan.
Cau hoi C# nao thuong gap nhat?
Cac cau hoi pho bien gom kieu gia tri va kieu tham chieu, record va class, cach async/await hoat dong, nguy co cua async void ngoai event handler va thoi diem LINQ thuc thi do deferred execution. Trong phong van hien dai, cac chu de nay thuong duoc dat duoi dang tinh huong code review hoac su co san pham.
Vong thiet ke he thong .NET thuong bao gom gi?
Cac tinh huong co the la thiet ke rate limiter cho API da tenant, dich vu thong bao, bo xu ly background job hoac endpoint thanh toan co idempotency. Nha phong van danh gia cach ban lam ro yeu cau, chon phuong an, xu ly partition, loi, consistency va he qua khi kho dung chung bi ngung hoat dong.
.NET co con nhieu nhu cau trong nam 2026 khong?
Co. .NET van duoc su dung rong rai cho ung dung doanh nghiep, web API, dich vu dam may va microservices. Nhu cau tap trung vao lap trinh vien nam vung .NET hien dai, .NET 10 va C# 14 thay vi chi biet cac mau cu cua .NET Framework.
Neu bai viet nay cho thay mot khoang trong kien thuc, hay bat dau bang viec luyen tap cac tinh huong thay vi hoc thuoc dinh nghia. Hay tu tra loi, neu ro danh doi, dua ra vi du tu san pham va luon chuan bi cho cau hoi truy van tiep theo.
Chuc ban phong van thanh cong va lap trinh vui ve!
