I’ve conducted more than 200 job interviews since May of 2015 for applicants at SendBird. Given our steep growth rate over the past two years, these interviews have been happening with more frequency.
I always make time at the end of the interview to listen to the candidate and answer any questions they may have about the job and the company. Today, I will ponder and share two of the most frequently asked questions. So, if I get the same question again, I hope that applicants will be able to see my honest and well-organized thoughts on this page.
Sendbird is a leading provider of chat and messaging solutions for mobile apps and websites. With a growing developer community and expanding list of high-profile customers, Sendbird is an exciting company for software engineers and product managers to launch their careers. This article provides an in-depth guide to mastering Sendbird interviews, including tips for technical coding challenges, product design questions, and recommended strategies for nailing the behavioral interview. Arm yourself with this knowledge to stand out in your Sendbird job interview.
Overview of Sendbird’s Interview Process
The Sendbird interview process typically consists of 3 rounds
Round 1 Initial phone/video screening focused on core competencies for the role. For engineering, expect questions on data structures and algorithms Product managers will be assessed on product sense
Round 2 Onsite or remote technical interviews with 2-4 engineers. Coding challenges test your skills in languages like Java, JavaScript, React Native. Design questions evaluate product intuition.
Round 3: Onsite with hiring manager. This round focuses heavily on cultural fit and behavioral competencies. Leadership principles and collaboration abilities are evaluated.
While each role differs slightly, Sendbird interviews universally test both hard technical skills and soft behavioral traits like communication, leadership potential, and alignment with Sendbird’s values.
8 Must-Know Technical Questions
Here are 8 commonly asked Sendbird technical interview questions to expect:
Q1: Difference between WebSocket and REST API?
WebSockets allow full-duplex communication between client and server, providing real-time data transfer. REST APIs rely on HTTP requests/responses and are stateless. Know the pros/cons of each.
Q2: Explain how you would design a chat feature for an app.
Highlight considerations like architecture, scaling, messaging protocols, groups vs channels, push notifications, offline support. Demonstrate strong technical design skills.
Q3: How is data stored and synced across devices in a chat app?
Discuss using a database like MongoDB to store message data and user info. Explain synchronization to ensure consistency across clients via websockets or services.
Q4: Balance API robustness with speed for a messaging platform.
Improving API robustness (e.g. input validation) may impact speed. Discuss intelligent caching, asynchronous processing, and horizontal scaling to achieve both.
Q5: Optimize a chat app for low-powered mobile devices.
Suggest optimizing payload sizes, efficient data structures, lazy loading, image compression, and performance profiling to identify bottlenecks.
Q6: How would you handle surge traffic spikes in a chat system?
Propose load balancing, autoscaling groups, caching, and progressively degrading nonessential functions as strategies to gracefully handle spikes.
Q7: What metrics would help monitor performance of a chat infrastructure?
Key metrics could include: active connections, message throughput, latency, uptime, API errors, database load, etc. Metrics should provide visibility into current state and projections.
Q8: Debug an issue causing high latency in a chat API.
Outline methodically isolating the problem through metrics review, logs analysis, profiling, stress testing, etc. Explain how you would prioritize fixes.
Preparing concise, structured responses to questions like these will showcase your technical acumen in Sendbird’s core domains.
5 Must-Know Sendbird Product Design Questions
For PM interviews, expect more product sense and design questions like these:
Q1: How would you design a user onboarding flow for a new chat app?
Discuss critical components like account setup, profile creation, contact access, tutorial, etc. Onboarding should ease new users into core functionality.
Q2: Suggest features to foster user engagement in a new messaging app.
Propose social features like profiles, communities, gamification, etc. that incentivize activity beyond just messaging. Consider psychological drivers.
Q3: How would you validate new features or changes in an existing chat product?
Highlight importance of data analytics, user surveys, focus groups, and staged rollouts for garnering feedback on new features prior to wide launch.
Q4: What key metrics would you track for a chat product and why?
Examples include DAU/MAU, session length, messages per user, response time, retention by cohort. Metrics should trace engagement, performance, and user lifecycle.
Q5: How would you A/B test new UI options for a chat app?
Discuss splitting sample populations, analyzing for statistical significance of metrics like engagement, converging iteratively on optimal UI. Avoid bias by randomizing groups.
For PM candidates, focus on conveying product intuition, strategic decision-making, and strong analytical skills in your responses. Back up ideas with data-driven rationale.
6 Behavioral & Cultural Fit Interview Questions
Sendbird’s behavioral interview will assess your soft skills and cultural fit through questions like:
Q1: Tell me about a time you faced a conflict on a team. How did you handle it?
Showcase conflict management skills and focus on resolution through communication and compromise. Demonstrate resilience and emotional intelligence.
Q2: Describe a challenging technical issue you faced. How did you approach troubleshooting it?
Illustrate structured problem-solving, technical perseverance, and your ability to break down complex issues systematically.
Q3: What would your manager and colleagues say about your work style?
Share qualities like responsibility, teamwork, positivity, and relationship building. Align with Sendbird’s collaborative culture.
Q4: Why do you want to work at Sendbird specifically?
Show passion for Sendbird’s Chat product and mission. Highlight overlaps with your own values and motivators.
Q5: How do you stay updated on the latest industry trends and technologies?
Demonstrate continuous learning through activities like reading, side projects, open source involvement, and engagement with tech communities.
Q6: Where do you see your career 5 years from now?
Articulate your long-term vision and developmental goals. Explain how this role would support your professional growth.
Come prepared to demonstrate the human skills that set you apart, like communication, empathy, positivity, and growth mindset. Use personalized stories and examples to prove these competencies.
How to Crush Your Sendbird Interview
Here are 5 tips for interview success:
-
Practice extensively – Use sites like LeetCode to sharpen coding skills. Rehearse answers to common questions out loud.
-
Highlight alignment – Identify overlaps between your values and Sendbird’s mission. Show you’re excited by the products and problems they tackle.
-
Ask thoughtful questions – Inquire about company roadmap, team culture, mentorship programs. Show your engagement.
-
Watch your behavior – Mirror positive body language and remain cool under pressure during technical assessments.
-
Follow up promptly – Send thank you notes to reinforce your continued interest and value-add.
With rigorous preparation, you can demonstrate technical excellence and human skills that will make you shine in your Sendbird interview. Show them you have what it takes to join this fast-growing company. You’ve got this!
Clear expectations & transparent communication
At that time, SendBird’s offer included 1) the smallest share of equity (which was one of the most important things to me), 2) an unclear job title, and 3) a pay package that wasn’t as good as the others.
Nevertheless, I was always and clearly told the reason for the proposal and its philosophical background. This made me trust that the company’s vision was real. Not only was the contract in the Stock Purchase Agreement well-written, but it was also short and pretty standard for the industry.
Unfortunately, the other two offers had a lot of good points, but I could only hear about them over the phone, which made it hard for me to check if they were real. Also, their contracts had a (seamingly debatable) poison clause that gave them limited voting rights and an oddly designed vesting period.
Two additional factors affected my decision, and they are as follows:
Why did I join the company SendBird?
Remember, it was the end of March 2015. At the time, I had just finished a deal to sell KKR, a global private equity fund, most of Ticket Monster, which was one of the biggest Korean mobile shopping apps at the time. The price was about $850M. I thought about starting my own business at first, but I quickly realized I didn’t have enough work experience in an early-stage company or the connections to put together a team. I therefore went to seek out startups that shared my business aspirations.
When I met John Kim, CEO and co-founder of SendBird (then called JIVER), on April 27, 2015, I already had two offers from other startups to join as an early member or as a member of their senior management team. I chose SendBird for the following reasons:
As you might have guessed, when I was looking for my next step, I wanted to talk to someone who had been an entrepreneur more than once so I wouldn’t have to make as many mistakes the first time around. This is why I liked the co-founders of SendBird, who started and shut down their first company together, Paprika Lab.
Also, it was interesting to see four grown men work together as founding members instead of having one founder also be the CEO of the company. Having a group was helpful because they could share their thoughts and experiences and also help each other out by covering each other’s weaknesses and building on each other’s strengths. Because of how this group works, I still think it was a good idea for me to join SendBird. Early startups usually have to make a lot of decisions, so having a group of founders work together lowers the chance that senior management will lose their cool.
SendBird’s Interview with Happyfresh
FAQ
What is the Sendwave interview process?
Why should we hire you?
Is it okay to ask for interview questions beforehand?
Can you ask for interview questions in advance as a reasonable adjustment?
