Senior Software Engineer

Skills every developer needs, in any language: code design, testing, data and distributed systems.

Good code

Clean Code

Good names, small functions, readable code

SOLID

Five basic object-oriented design rules, with examples

Design patterns

Strategy, Decorator, Factory, Mediator and more

Dependency Injection

Service lifetimes and common mistakes

Code review

What to look for and how to give feedback

Data

SQL and indexes

Query plans, the right index, paging on big tables

Transactions and isolation levels

Lost updates, deadlocks and locks

Caching patterns

Cache-aside, cache invalidation, stampede

NoSQL

MongoDB and when to use it instead of SQL

APIs and security

Security

OWASP Top 10, secret management, encryption

Authentication and authorization

JWT, OAuth2, OpenID Connect and policies

Idempotency

One request, any number of times, one result

Testing and delivery

Unit tests with xUnit

What a good test looks like, mocks and fakes

Integration tests

Testcontainers and WebApplicationFactory

TDD

Test first, then code: red, green, refactor

CI/CD

Pipelines, automated tests, safe deploys

Docker

Small images, multi-stage builds, layers

In production

Structured logging

Serilog, log levels, correlation IDs

Metrics and alerts

Prometheus, Grafana and good alerts

Resilience with Polly

Retry, circuit breaker, timeout and retry storms

System design

Horizontal scaling, load balancing, sharding, replicas

Estimation and planning

Estimating work, splitting big tasks, risk