Senior Developer

Introduction

The Expert Services team helps customers and partners implement commerce, content management, and digital marketing solutions with sound technical practices. In this role, you will support architecture, development, third-party integration strategy, and application performance tuning across real customer projects.

This is a dynamic customer-facing position, so previous consulting or services experience is important. You will work with close-knit teams serving international clients, with many projects built on Microsoft technologies such as ASP.NET.

Job Responsibilities

• Exceed your billable utilization target.
• Manage multiple application development projects simultaneously.
• Assist with the development of service estimates as required.
• Provide best practice advice and guidance to clients and partner development teams.
• Deliver high-quality technical consultancy and implementation work at partner or client locations.
• Participate in partner projects in-house or on-site, delivering production-ready code and troubleshooting live and development environments.
• Develop, customize, and implement features based on Optimizely products upon request.

Knowledge and Experience

• Prior experience in .NET projects, including .NET and ASP.NET.
• Experience with e-commerce and Optimizely CMS is a strong plus.
• Experience with Web API development.
• Knowledge of JavaScript, HTML5, and CSS.
• Experience with TFS, Git, Jira, or other source control and delivery tools.
• Front-end engineering skills with object-oriented JavaScript and responsive web design are an advantage.
• Experience with at least one JavaScript library or framework, such as AngularJS, React, or Vue.
• Experience with Microsoft data technologies such as ADO.NET, SQL Server, and Entity Framework.
• Ability to implement and optimize .NET server-side technologies.
• Strong understanding of design patterns and design principles.
• Good problem-solving skills.
• Proficiency in code review and code refactoring.
• Experience working in an Agile or Scrum software development environment.
• Ability to work across multiple projects and collaborate well in a team.
• A positive attitude toward self-testing and self-learning.
• Tertiary qualifications in Computer Science or equivalent experience.
• Good written English, with spoken English a strong plus.
• Ability to take ownership of tasks and projects with a service-oriented mindset.
• Ability to troubleshoot software issues.
• Comfort working with a wide variety of technologies and end users.

Education

• Bachelor's degree preferred or equivalent work experience.

Competencies

• Driving Projects to Completion
• Critical Thinking
• Acquiring Information
• Evaluating and Implementing Ideas
• Serving Customers

About Optimizely

At Optimizely, we're on a mission to help people unlock their digital potential. We do that by reinventing how marketing and product teams work to create and optimize digital experiences across all channels. With Optimizely One, our industry-first operating system for marketers, we offer teams flexibility and choice to build their stack their way with our fully SaaS, fully decoupled, and highly composable solution.

We are proud to help more than 10,000 businesses, including H&M, PayPal, Zoom, and Toyota, enrich their customer lifetime value, increase revenue and grow their brands. Our innovation and excellence have earned us numerous recognitions as a leader by industry analysts such as Gartner, Forrester, and IDC, reinforcing our role as a trailblazer in MarTech.

At our core, we believe work is about more than just numbers -- it's about the people. Our culture is dynamic and constantly evolving, shaped by every employee, their actions and their stories. With over 1500 Optimizers spread across 12 global locations, our diverse team embodies the "One Optimizely" spirit, emphasizing collaboration and continuous improvement, while fostering a culture where every voice is heard and valued.

Benefits

• We are Vietnam Best IT companies 2026 by ITviec.
• Hackdays for self-studying and researching any IT-related subjects.
• 5 working days/week with flexible working time and no overtime.
• Annual unforgettable company outing.
• International, professional, creative working environment and talented teams.
• Onsite opportunities in Europe and US.
• Common cultural-sportive- art Clubs and activities, sponsored and/or supported by the Company (Ex: Football, GYM, Swimming, Guitar, English…).
• Powerful workstation: Core i7-9700, 16-32 GB RAM, 02 x QHD 2560x1440 monitors (2K resolution).
• 100% official salary during the probation period, 13th month salary, annual salary raise.
• Up to 03 extra paid-leave days per year.
• Social, Health and Unemployed Insurance are based on 100%.
• Gross salary and fully paid by Company.
• Extra bonus at $ 60 per special occasions (Birthday, Labor Day, National Day, Solar New year, Lunar New Year).
• Lunch allowance at $30 per month.
• Baby allowance for a child under 03 years old is $ 12 per month.
• AON Premium Healthcare Insurance package for employees and their children up to 18 years old.
• Daily various foods, drink, and seasonal fresh fruits.