Senior / Lead Fullstack Engineer

Aplazo

Senior Fullstack Engineer designing backend services and mobile applications for fintech company Aplazo. Shipping features to millions of users across Latin America with a focus on quality and architecture.

Posted 7/27/2026full-timeRemote • 🇲🇽 MexicoSeniorWebsite

Core Competencies

Role fit

Core Competencies

Use this summary to align your resume positioning with the role.

Demonstrates expertise in fullstack development with a strong focus on backend technologies such as Java/Spring and mobile development using Flutter/Dart. Proficient in API design, cloud infrastructure, and observability practices, while effectively communicating technical concepts across diverse teams.

Highest-signal resume keywords

Fullstack DevelopmentJava/Spring Backend SkillsFlutter/Dart Mobile DevelopmentAPI Design (REST, GraphQL)Cloud Infrastructure (AWS)

ATS Keywords

Tailor your resume

Applicant Tracking System Keywords

Tip: use these terms in your resume and cover letter to boost ATS matches.

Hard Skills

Fullstack DevelopmentJava/SpringFlutter/DartAPI DesignPostgreSQLMongoDBAWSMicroservicesUnit TestingCI/CD Pipelines

Soft Skills

Technical DocumentationMentoringCommunicationFeedback

Tools & Technologies

DataDogECSLambda

Industry Keywords

B2C ProductsFintechPayments PlatformsEvent-Driven Architectures

Tech Stack

Tools & technologies

AWSCloudDartFlutterGoGraphQLJavaMicroservicesMongoDBPostgresPythonSpring

About the role

Key responsibilities & impact

End-to-end product features — from database schema to API design to the mobile experience users interact with
Internal tools, merchant-facing platforms, and customer-facing mobile flows
Observability from day one — SLOs, alerts, dashboards — so you know when something's broken before users do
Systems designed to be handed off: documented, tested, and legible to the engineer who touches it six months later
Design and implement features across mobile and backend, owning the full surface area
Contribute to (E2) or lead (E3) architecture and design decisions — write proposals, present trade-offs, make calls
Conduct rigorous code reviews — catching correctness issues, security gaps, and opportunities to mentor
Respond to and resolve production incidents, and leave runbooks better than you found them
Use AI tools daily — not as a crutch, but as a force multiplier for speed, testing, and exploration
Help engineers around you grow, especially through pairing, thoughtful feedback, and honest code review (E3)

Requirements

What you’ll need

3+ years of fullstack experience (5+ for E3), ideally in B2C products
Strong backend skills: Java/Spring as the primary stack; Python or Go a plus
Strong mobile skills: Flutter/Dart — comfortable building real production apps, not just gluing widgets together
Solid experience with APIs (REST, GraphQL), databases (PostgreSQL, MongoDB), and cloud infrastructure (AWS: ECS, Lambda)
Familiarity with microservices and event-driven architectures
Good testing instincts — unit, integration, and enough end-to-end to actually trust your builds
Comfortable with CI/CD pipelines, observability tools (DataDog), and deployment in cloud environments
Awareness of how payments platforms work — the flows, the constraints, the failure modes that matter in a BNPL or fintech product
Writes clear technical documentation — the kind that actually gets read
Explains trade-offs to engineers and non-engineers alike, without condescension or jargon
Fluent in Spanish; working English for cross-team collaboration with our India and international colleagues

Benefits

Comp & perks

A small, senior engineering team that moves fast and argues about the right things
Real ownership: you'll ship features that reach millions of users, not work on internal tooling for years
A culture that takes AI seriously — we run a company-wide hackathon with agentic AI as the theme, and we expect engineers at all levels to be fluent
A team that invests in learning — through engineering workshops, architecture reviews, and direct exposure to hard production problems
An honest engineering culture: we write RFCs, do real code reviews, and have the hard conversations before shipping