Senior Backend Engineer

Raenest is seeking a highly skilled Senior Backend Engineer to drive the design, development, and optimization of backend systems that power our global financial infrastructure for African businesses and talent. You will architect and build scalable microservices, ensure high system reliability, lead technical decision-making, and collaborate cross-functionally to deliver features that support payment operations, and compliance workflows.
You will work across a modern stack that includes JavaScript/TypeScript, Node.js, PostgreSQL, Redis, AWS tools, GitHub, CircleCI, and microservices. The role requires deep technical skill, leadership, and a strong ownership mindset.

Key Responsibilities

1. Backend Development & Architecture
2. Design, build, and maintain backend services using Node.js (JS/TS) with clean, scalable, maintainable code.
3. Architect and implement distributed microservices with clear domain boundaries.
4. Develop and maintain RESTful and event-driven APIs, ensuring reliability and backward compatibility.
5. Design robust data models and queries for PostgreSQL and implement caching layers using Redis.
6. Implement asynchronous processing using AWS SQS, Lambda workers, or containerized background jobs.

7. Build internal tooling (automations, integrations, CLI utilities).

8. System Scalability & Performance

9. Optimise application performance, latency, throughput, and resource usage.

10. Design for high availability and fault tolerance across microservices.

11. Implement monitoring, tracing, and logging using AWS tools or third-party platforms.

12. DevOps, CI/CD & Cloud Infrastructure

13. Build and maintain CircleCI pipelines for tests, builds, deployments, and automated workflows.

14. Work with AWS (Lambda, ECS/Fargate, SQS, SNS, CloudFormation, RDS, Secrets Manager).

15. Maintain IaC templates, deployment strategies, and blue/green or canary releases.

16. Collaborate with DevOps for observability, alerting, and cost optimization.

17. Code Quality, Testing & Documentation

18. Write unit, integration, and end-to-end tests.

19. Participate in code reviews, tech audits, refactoring, and enforcing best practices.

20. Maintain architectural documentation, diagrams, and API specifications.

21. Ensure security best practices (OWASP, input validation, encryption, credential handling).

23. Cross-functional Collaboration

24. Work with Product Managers and Designers to shape feature requirements and technical trade-offs.

25. Collaborate with frontend, mobile, and QA engineers for cohesive product delivery.

6.** Leadership & Mentorship**
Mentor junior and mid-level backend engineers through pairing, code reviews, and guidance.

Lead technical initiatives, propose architecture improvements, and drive long-term engineering excellence.

Champion engineering culture, documentation standards, and knowledge-sharing.

Required Skills & Experience
Core Technical Skills

• 5–8+ years professional backend engineering experience.
• Expert-level proficiency in Node.js with JavaScript & TypeScript.
• Strong SQL and schema design experience with PostgreSQL.
• Experience with distributed caching using Redis.
• Deep knowledge of AWS serverless and containerised services (Lambda, ECS/Fargate, API Gateway, S3, CloudFormation, SQS/SNS).
• Experience building, deploying, monitoring, and scaling microservices.
• Strong CI/CD experience with GitHub, CircleCI, unit test runners.
• Experience reading, designing, and maintaining complex APIs and event-driven systems.

Architecture & Patterns

• Strong competency in domain-driven design, event-driven design, and transactional boundaries.
• Experience with distributed systems challenges (rate-limiting, idempotency, retries, eventual consistency).
• Experience with double-entry ledger and accounting for developers.
• Understanding of payment systems, identity, or compliance flows (bonus).