Freelance Java Backend Developer Jobs in San Antonio, TX

Mindrift is looking for skilled Bot Developers (WhatsApp Business API, Telegram Bot API, Discord API) to join the Tendem project (https://tendem.ai/) and build conversational bots and messaging-platform integrations for real-world applications. In this role, you'll use your bot engineering expertise, conversational design skills, and quality-focused approach to build reliable, useful bots and messaging integrations that deliver a great user experience. This part-time remote opportunity is ideal for professionals with hands-on experience building messaging bots, working with platform APIs and webhooks, and implementing conversational logic.

What We Do 

The Mindrift platform connects specialists with innovative technology projects. Our mission is to help develop high-quality AI technologies by combining real-world expertise from professionals across the globe with advanced AI development efforts.

About the Role 

This is a freelance role for a Tendem project. As a Bot Developer, you'll design, build, and refine messaging bots for one or more messaging platforms, including WhatsApp, Telegram, Discord, Slack, and similar platforms - for use cases such as customer service, appointment booking, order taking, content delivery, moderation, and automated notifications.

Key Responsibilities

• Build bots for one or more messaging platforms, such as WhatsApp (Business API / Cloud API), Telegram (Bot API), Discord, Slack and similar messaging platforms.
• Design and implement conversational flows, dialogue state, and fallback handling.
• Integrate bots with LLMs (OpenAI, Anthropic, or similar) for natural language responses where appropriate.
• Connect bots to backend services, databases, CRMs, and third-party APIs (booking systems, payment, content sources).
• Handle webhooks, rate limits, and platform-specific message formats (interactive messages, buttons, media, templates).
• Review, debug, optimize, and refactor bot implementations to improve correctness, reliability, maintainability, and graceful error handling.
• Implement logging, monitoring, and recovery so bots stay healthy in production.

Requirements and benefits

Educational qualifications

• At least 3 years of relevant experience backend, integration, automation, or bot development experience (required).
• Bachelor's or Master's Degree in Computer Science, Engineering, Information Technology, or related technical fields is a plus.

Academic and/or Professional Experience

Candidates should have a strong foundation in bot development, messaging platform integrations, and building reliable conversational workflows. We are looking for specialists who can design and maintain production-ready bots, work confidently with APIs, webhooks, and backend services, and build stable, user-friendly bot experiences. Strong problem-solving skills, attention to detail, and the ability to work independently are essential.

Technical Skills (Essential)

• At least 1 year of hands-on experience building bots for at least one major messaging platforms (WhatsApp, Telegram, Discord, Slack, or similar) is required
• Strong command of Python or Node.js for backend bot logic.
• Solid experience with REST APIs, webhooks, OAuth, and async request handling.
• Experience with relational or NoSQL databases for storing conversation state and user data.
• Familiarity with LLM APIs (OpenAI, Anthropic) and prompt design for conversational use is a strong plus.
• Understanding of platform-specific limits, message templates, and approval flows (e.g., WhatsApp template messages).
• Experience with hosting and deployment (Docker, serverless, VPS, or PaaS)

Additional requirements

• Strong attention to detail and commitment to bot reliability - no silent failures, no broken flows.
• Self-directed work ethic with the ability to design and ship complete bots independently.
• Portfolio or examples of bots you've built (required).
• English proficiency: Upper-intermediate (B2) or above (required)

Project time expectations 

For this project, tasks are estimated to require around 10-20 hours per week during active phases, based on project requirements. This is an estimate, not a guaranteed workload, and applies only while the project is active.

Compensation 

On this project, contributors can earn up to $60 per hour equivalent, depending on their level and pace of contribution.

Compensation varies across projects depending on scope, complexity, and required expertise. Please note that other projects on the platform may offer different earning levels based on their requirements.

Why this freelance opportunity might be a great fit for you? 

• Work fully remote on your own schedule with just a laptop and stable internet connection.
• Apply your expertise to real-world technology projects while gaining experience building high-quality solutions for a global platform.
• Participate in performance-based bonus programs that reward high-quality work and consistent delivery.