Backend Developer (Python, FastAPI)

SETA INTERNATIONAL VIETNAM - RECRUITMENTJob Title: Backend Developer (Python, FastAPI)We are looking for a Backend Developer (Python) with at least 3 years of experience to join a project where deep business understanding matters as much as clean, well-designed code.In this role, you will own backend features end-to-end: working with international stakeholders to understand and analyse the business domain, designing and building APIs with FastAPI, and optimising database performance. We are looking for someone who takes real ownership of what they build, learns a new domain fast, and enjoys hard problems rather than avoiding them. For engineers who want it, there is a clear growth path towards a technical leadership role.ResponsibilitiesDesign, develop, and maintain backend services and RESTful APIs using Python and FastAPI.Work directly with clients and product owners to explore, analyse, and clarify business requirements, then translate them into technical solutions.Take end-to-end ownership of assigned modules: requirement analysis, design, implementation, testing, release, and production support.Optimise database performance: schema and data model design, query tuning, indexing strategy, execution plan analysis, and resolving bottlenecks.Investigate and solve complex or ambiguous technical problems where the answer is not documented anywhere.Safeguard code quality, security, and maintainability through code reviews, automated tests, and engineering best practices.Write and maintain technical documentation for the domain logic and services you own.Join regular online meetings with international clients (evening meetings may be required).Mentor junior members and progressively take on technical leadership responsibilities (for candidates with leadership ambition).Your Skills & ExperienceAt least 3 years of experience in backend development with Python.Strong hands-on experience with FastAPI (or Flask/Django with a clear willingness to move to FastAPI), asynchronous programming, and Pydantic.Solid database skills with PostgreSQL or MySQL: data modelling, query optimisation, indexing, transactions, and profiling slow queries.Strong business analysis mindset: able to ask the right questions, challenge unclear requirements, and understand the "why" behind every feature.High ownership: comfortable being the accountable person for a module or a business domain, not just an executor of tickets.Fluent English communication (speaking and writing) — able to work directly with international clients and stakeholders without a translator.Fast learner with a proven record of picking up unfamiliar business domains or technologies quickly.Willingness to work on hard problems: performance issues, unclear specifications, legacy code, and deep debugging.Experience with Git, Docker, and CI/CD workflows.Experience with Cloud platforms (Azure or AWS is a plus).Nice to HaveAmbition and potential to grow into a Technical Lead / Team Lead role.Experience with Redis, Celery, or message queues (Kafka, RabbitMQ).Experience with data-intensive systems, ETL/data pipelines, or time-series data.Experience with testing frameworks (pytest) and observability tools (Prometheus, Grafana, OpenTelemetry).Understanding of security best practices (OWASP, authentication and authorisation design).Background in a domain-heavy industry such as energy, finance, healthcare, or logistics.Exposure to integrating AI/LLM capabilities into backend services.BenefitsSalary: NegotiableAttractive salary & performance-based bonus.Full benefits according to Vietnam Labor Law (Social & Health Insurance).International, professional, young and innovative working environment.A clear technical growth path, including mentoring and leadership opportunities.Opportunity to work directly with global experts and join technology conferences/workshops.Holidays and paid leave according to Vietnam Labor Law.Company trip & team building activities.