Senior Software Engineer Jobs in Mendon, MA (NOW HIRING)

We are seeking an experienced Senior Software Engineer to join our team. In this role, you will work across the full application stack to design, develop, and test features in our cloud-based platform. You will collaborate closely with cross-functional partners to deliver high-quality, scalable solutions. We’re looking for someone who thrives in a fast-paced, agile environment and enjoys solving complex technical challenges. If you’re passionate about building innovative software and contributing to a collaborative engineering culture, we’d love to connect.

Who We Are

BigTime is the AI-powered professional services platform enabling intelligent decisions and delivering profitable growth. We’ve proudly been featured on Inc.’s 500 Fastest Growing Companies in America four years in a row and named one of Crain’s Best Places to Work three years running.

Our flagship SaaS platform powers 2,700+ consulting firms worldwide, tracking over $4B in billable time each year. We’re on a mission to become the leading AI-driven platform guiding professional services organizations to excel in delivery, resource, and financial management.

The Opportunity 

As a Senior Software Engineer, you’ll take ownership of designing and building systems that power real, high-impact workflows for our customers. You’ll work on problems that go beyond basic CRUD — things like orchestrating complex data flows, integrating with external platforms, and creating automation that removes friction from everyday work.  You’ll help shape the architecture of our platform, make decisions about how things scale and operate in production, and build software that’s reliable and easy to evolve. This role gives you room to dive deep: one day you might be sketching out a new service boundary or designing an API contract, and the next you’re rolling up your sleeves to debug a tricky edge case in the stack.  

You won’t be doing this in a vacuum. You’ll work with a strong engineering team that values clear thinking, pragmatic technical choices, and building things the right way. Your contributions will directly influence the direction of the product and how thousands of users experience it.

What You’ll Do

• Design, build, and enhance core application features using React, C#, ASP.NET MVC, and T-SQL

• Own and improve critical system integrations (Jira, Smartsheet, Salesforce, HubSpot, QuickBooks Online, Sage Intacct), focusing on reliability, observability, and long-term maintainability.

• Lead code reviews, influence coding standards, and help raise the quality bar across services and shared components.

• Work closely with product, support, and engineering teams to solve complex problems and implement scalable, high-quality features.

Who You Are

• You have 5-10+ years of hands-on engineering experience, with .NET Framework or strong experience in another backend language paired with a willingness to learn is equally valuable.

• You’re comfortable working across the stack and understand the fundamentals of building and scaling web applications (C#, ASP.NET MVC, T-SQL, or equivalent tech).

• You’re comfortable working in a sprawling, legacy codebase and understand the caution required when adding features and making improvements.

• You know modern front-end tools (HTML, CSS, JavaScript/Typescript, React/Svelte/Solid, etc.) and enjoy building clean, usable interfaces.

• You have solid grounding in software design principles (e.g. OOP, SOLID, testing practices) and know how to structure code for long-term health.

• You take ownership of your work, manage your time well, and can drive a project from concept to deployment without needing constant direction.

• You thrive in environments where you collaborate with other stakeholders and help create clarity for the team.

• You’re curious, practical, and quick to learn new technologies, frameworks, or approaches.

• You are a team player who believes no task is beneath you.

What We Offer

• Competitive salary and an annual bonus

• Company pays 100% of benefits, including medical, dental, vision, disability and life insurance

• 401k with generous company match

• Paid Parental Leave 

• Generous time off and paid company holidays - 35 days off the first full year of employment

• Flexible work environment with remote opportunities

• Hybrid work schedule

• Company provided latest technology & software tools

The salary for this position is $150,000.00 annually. In addition to base salary and a competitive benefits package, this position may be eligible for additional types of compensation such as bonuses.

Applicants must be authorized to work in the U.S. BigTime Software, Inc. is proud to be an Equal Opportunity Employer. All qualified applicants will receive consideration for employment without regard to race, color, religion, sex, national origin, disability, protected veteran status, or any other characteristic protected by law.

Your Right to Work - In compliance with federal law, all persons hired will be required to verify identity and eligibility to work in the United States and to complete the required employment eligibility verification document form upon hire.