Mid Level Software Engineer – Backend

Billor

Software Engineer Backend designing scalable APIs and optimizing databases for FinTech trucking ecosystem. Focusing on performance and reliability of back-end services.

Posted 7/3/2026full-timeJoinville • 🇧🇷 BrazilMid-LevelSeniorWebsite

Core Competencies

Role fit

Core Competencies

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Demonstrates expertise in designing and evolving domain APIs using NestJS and TypeScript, with a strong focus on clean architecture, event-driven communication, and PostgreSQL optimization. Proficient in implementing authentication and authorization mechanisms while ensuring reliability through comprehensive testing and collaboration with front-end teams.

Highest-signal resume keywords

NestJSTypeScriptPostgreSQL Schema DesignEvent-Driven ArchitectureREST API Design

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Hard Skills

API DesignObject-Oriented ProgrammingQuery OptimizationUnit TestingIntegration Testing

Tools & Technologies

DockerRedisGoogle CloudGitAgile Methodologies

Industry Keywords

MicroservicesSSOJWTPub/SubLayered Architecture

Tech Stack

Tools & technologies

CloudDockerJavaScriptMicroservicesNode.jsPostgresRedisSQLTypeScript

About the role

Key responsibilities & impact

Design and evolve domain APIs in NestJS/TypeScript following a strict layered architecture: thin controllers, business logic in the service layer, data access isolated in repositories.
Build event-driven communication between services with Pub/Sub, using patterns like transactional outbox and idempotent consumers to guarantee reliability.
Model and optimize PostgreSQL schemas and queries — proper types, indexing, and normalization decisions (when a field should really be a related table).
Use Redis for caching and session data, with deliberate TTL and invalidation.
Design clean, versioned REST contracts (plural resources, correct HTTP verbs and status codes, standardized JSON response envelopes).
Implement authentication and authorization (SSO/JWT via a central gateway), always revalidating permissions on the server — never trusting the client.
Collaborate with front-end/BFF engineers on typed, contract-first API interfaces.
Write unit and integration tests as a first-class part of delivery.
Participate in code and architecture reviews, and help make (and document) sound architectural decisions.

Requirements

What you’ll need

Solid experience with NestJS and the Node.js ecosystem.
Strong TypeScript and object-oriented / clean-architecture fundamentals (SOLID, separation of concerns, dependency inversion).
Deep PostgreSQL knowledge: schema design, indexing, query optimization.
Hands-on experience with event-driven / message-based architectures (Pub/Sub, queues, or similar) — retries, idempotency, ordering.
Comfort with layered / hexagonal service design and keeping business logic out of controllers and infrastructure.
Experience designing and consuming REST APIs at scale (versioning, contracts).
Authentication & authorization fundamentals (JWT, SSO, OAuth concepts).
Docker and containerized deployments.
Git and Agile workflows (Scrum/Kanban).
Ability to write unit and integration tests to ensure reliability.
Strongly Desired Experience deploying to Google Cloud (Cloud Run, Cloud SQL, Pub/Sub, Secret Manager, Cloud Scheduler/Jobs).
Redis for caching and real-time data.
Experience in distributed / multi-service (microservices) systems and monorepo / shared-library setups.
A reuse-first mindset: extending shared platform code instead of duplicating.

Benefits

Comp & perks

Health and dental plan
Paid vacation
Holidays off
Parental Leave
Wedding Leave
Flash card
Wellhub