Senior Back End Developer (JavaScript, NextJS)

Role: Senior Backend Engineer (JavaScript/TypeScript, NestJS)

Location: Lagos (hybrid) or Remote within GMT–1 to GMT+3

Team: Platform Engineering

Type: Full-time

About us

We’re building the operating system for energy, mobility, and auto-care across Africa. Our platform powers consumer apps, fleet automation, rescue, car care, marketplace, and enterprise integrations. Reliability, safety, and scale are at the core of everything we build.

What you’ll do

- Design, build, and operate scalable, secure backend services in JavaScript/TypeScript using NestJS and the broader Node.js ecosystem.

- Own core service domains end-to-end: ordering, routing/dispatch, pricing, payments, subscriptions, telematics, marketplace, and more.

- Model complex operational data with strong consistency (Postgres) and high-throughput caching (Redis).

- Build event-driven and streaming workflows using Kafka for real-time logistics, fraud detection, and notifications.

- Create clean, well-versioned APIs (REST & gRPC); define contracts and maintain backward compatibility.

- Implement reliable service patterns: background workers, sagas, idempotency, retries, rate limiting, queueing.

- Drive performance: p95/p99 latency, Node.js event loop profiling, DB query optimization, connection pooling.

- Implement SLOs, error budgets, distributed tracing (OpenTelemetry), dashboards, alerts; participate in on-call rotations.

- Collaborate on OAuth2/OIDC, RBAC/ABAC, secrets, and encryption with Security & DevOps.

- Mentor engineers, uphold code quality, and contribute to internal libraries, modules, and service templates.

Our Stack

- Languages / Frameworks

- JavaScript/TypeScript, Node.js

- NestJS, Express/Fastify

- TypeORM/Prisma, Zod/Valibot for validation

- pnpm, Yarn, Nx (optional)

- APIs

- REST (OpenAPI/Swagger)

- gRPC

- GraphQL gateway optional

- Messaging / Streaming

- Apache Kafka (or AWS MSK)

- Schema Registry (Avro/Protobuf)

- Data

- Postgres (OLTP)

- Redis (caching, locks, queues)

- ClickHouse/BigQuery for analytics

- Infrastructure

- Docker, Kubernetes, Helm, Terraform

- AWS/GCP (EKS/GKE, RDS, S3/GCS, CloudFront/Cloudflare)

- Observability

- OpenTelemetry, Prometheus/Grafana, Sentry

- Loki/ELK

- CI/CD

- GitHub Actions, ArgoCD/Jenkins

- Feature flags, canary & blue-green deploys

- Security

- OAuth2/OIDC (Keycloak/Cognito)

- JWT, mTLS, Vault/KMS

- Audit logging

What we’re looking for

- 7+ years engineering backend systems in production.

- 5+ years hands-on with JavaScript/TypeScript, NestJS, and Node.js at scale.

- Deep understanding of distributed systems: transactions, consistency models, partitioning, queueing, failure modes.

- Strong experience with Kafka: partitions, ordering, consumer groups, retries, DLQs.

- Proficiency in performance optimization: event loop profiling, async patterns, memory tuning.

- Solid SQL + Postgres skills: schema design, indexing, migrations (Prisma/Flyway/Liquibase).

- Security-first mindset: OAuth2/OIDC, RBAC, secrets, encryption, least privilege.

- Great communication and ownership; strong collaboration with Product, Ops, and Data.

- Nice to have: payments, reconciliation, logistics/dispatch, telematics, geospatial, multi-tenant SaaS, gRPC, Avro/Protobuf.

90-Day Success

- Ship a core NestJS service or major refactor with measurable wins (e.g., p95 latency −30%, error rate −50%).

- Establish golden signals/SLOs; implement distributed tracing across key flows.

- Deliver a resilient Kafka workflow with proper idempotency and monitoring.

- Document and publish a standard NestJS service template (logging, metrics, retries, CI/CD), and onboard others.

Compensation & Benefits

- Competitive salary + meaningful equity

- Health insurance, PTO, learning budget, equipment

- Relocation assistance for moves to Lagos

How to Apply

- Email handel@flud.link

- Include:

- Subject: Senior Backend (JS) – YourName

- Resume/LinkedIn

- System design write-up or architectural diagrams of something you built

- GitHub/portfolio or code samples (optional)

- Short note on a performance or reliability improvement you led

Interview Process

- Recruiter screen (30 min)

- Backend (JavaScript/TypeScript, NestJS) + Systems Design deep dive (60–90 min)

- Practical exercise: implement/extend a NestJS service in JavaScript/TypeScript with Kafka + Postgres (2–3 hours, compensated)

- Product & culture interviews (2 × 45 min)

- References + offer

Equal Opportunity

We value diverse perspectives and are committed to building an inclusive, high-performing team.

<