[Job 28143] Senior Developer Javascript (Vanilla), Rio de Janeiro/RJ

Description

Job Summary: We are seeking a Tech Lead / Vanilla Javascript Developer to join our data product development team for an Entertainment client, responsible for designing and implementing architectural improvements and serving as a technical reference. Key Highlights: 1. Work on data projects for clients in the Entertainment industry 2. Lead architectural improvements and refactoring of monoliths into microservices 3. Serve as a technical reference for multiple squads We are specialists in **technological transformation**, combining human expertise with AI to build scalable tech solutions. With over 8,000 CI&Ters worldwide, we have formed partnerships with more than 1,000 clients over our 30-year history. Artificial Intelligence is our reality. **Important**: If you reside in the Metropolitan Region of Campinas, your physical presence at the city offices will be mandatory, per our current attendance policy. We are looking for a **Tech Lead / Javascript (Vanilla) Developer** to join our data product development team and work with a client in the **Entertainment** industry. **Your responsibilities will include:** * Designing sustainable architectural improvements * Refactoring monoliths into microservices and modularizing embedded frontends * Taking a systemic approach to understand impacts across backend, video platform, devices, product, and user experience * Participating in architectural decision-making * Serving as a technical reference for multiple squads * Documenting architectural decisions (ADRs) * Working metrics-driven, with a culture focused on performance and quality. **For this challenge, it is important to have:** * **Availability for hybrid work, 2 days per week at the client's office (Rio de Janeiro/RJ);** * Strong experience with **Vanilla Javascript** * Deep mastery of **pure Javascript** (without excessive reliance on frameworks) * Solid understanding of: event loop, garbage collection, memory leaks, and DOM manipulation in constrained environments * Awareness of real hardware limitations: limited CPU, restricted memory, and legacy browsers * Experience with microservice architecture and distributed systems * Experience with synchronous and asynchronous communication * Experience with relational or non-relational databases * Experience with message brokers (Kafka, RabbitMQ or similar) * Knowledge of Idempotency * Knowledge of Retry and backoff * Knowledge of Circuit breaker * Knowledge of observability (logs, metrics, tracing) **Nice-to-have qualifications:** * Experience with applications running on embedded browsers * Experience with HLS and/or MPEG\-DASH, DRM (Widevine, PlayReady, FairPlay), and integration with custom or native players * Experience handling buffering, adaptive bitrate (ABR), playback error events, and player telemetry (QoE, QoS) * Experience with Caching and Performance \#LI\-AM2 **Our benefits:*** Health and dental insurance * Meal and food allowance * Daycare assistance * Extended parental leave * Partnerships with gyms and health & wellness professionals via Wellhub (Gympass) TotalPass * Profit and Results Sharing (PLR) * Life insurance * Continuous learning platform (CI\&T University) * Discount club * Free online platform dedicated to promoting physical health, mental health, and wellbeing * Pregnancy and responsible parenting course * Partnerships with online course platforms * Language learning platform * And many more More details about our benefits here: https://ciandt.com/br/pt\-br/carreiras At CI\&T, inclusion begins at first contact. If you are a person with disability, it is important to **submit your medical report during the selection process.** *Check which information must be included in the report by clicking here.* This way, we can ensure the support and accommodations you deserve. **If you do not yet have the qualifying medical report, don’t worry: we can support you in obtaining it.** We have a dedicated Health and Wellness team, inclusion specialists, and affinity groups who will support you throughout every stage. Count on us to walk alongside you on this journey.