Senior Golang Backend Engineer

Product: Flowtics Labeling
Location: Tehran, Iran | Primarily On-site, occasional WFH
Type: Full-time

About the Role

Flowtics Labeling is a crowdsourced image-annotation platform for creating high-quality AI/ML datasets. We manage annotation campaigns, peer review, contributor rewards, and dataset preparation.

We are hiring a Senior Go Engineer to build reliable backend services with a strong focus on Clean Architecture, distributed systems, and data processing. This role is exclusively for Flowtics Labeling, not our other projects.

Responsibilities

Build and maintain Go services and REST APIs.
Apply Clean Architecture, SOLID, domain-driven design, and clear separation of concerns.
Design domain models for campaigns, annotations, reviews, datasets, and rewards.
Design and optimize PostgreSQL schemas, migrations, indexes, transactions, and queries.
Build asynchronous workflows using NATS JetStream and AWS SQS.
Use Redis for caching and performance optimization.
Develop pipelines for validating, aggregating, and exporting ML datasets.
Implement retries, idempotency, error handling, and reliable message processing.
Write unit and integration tests; maintain technical documentation.
Optimize concurrency, memory usage, performance, and production reliability.
Participate in code reviews, architecture decisions, and incident debugging.

Requirements

5+ years of backend experience, including 3+ years with Go in production.
Strong knowledge of Go concurrency, goroutines, channels, HTTP, and profiling.
Practical experience with Clean Architecture, SOLID, and modular design.
Strong PostgreSQL and Redis experience.
Experience with REST APIs, messaging systems, and distributed applications.
Understanding of testing, data consistency, and failure recovery.
Familiarity with Docker, Git, Linux, and CI/CD.
Strong debugging, communication, and problem-solving skills.
Able to work regularly from our Tehran office, with occasional WFH by agreement.

Nice to Have

NATS JetStream, AWS SQS, Kubernetes, and AWS EKS.
Echo, GORM, Uber Fx, Cobra, and Viper.
Keycloak, OAuth2/OIDC, and Sentry.
Image annotation, data labeling, ML datasets, or data-quality methods.
Experience with payment, rewards, or ledger systems.

Tech Stack

Go, Echo, PostgreSQL, GORM, Redis, NATS JetStream, AWS SQS, Uber Fx, Docker, Kubernetes, AWS, Keycloak, Sentry, Swagger/OpenAPI.

What We Offer

Modern technologies, technical ownership, challenging backend problems, exposure to ML data infrastructure, and competitive compensation.

Work Model: Tehran office, primarily on-site, with occasional work-from-home flexibility.