Serverless WordPress Demystified

These are the slides from a talk given at WordCamp Canada 2025

Some of us love managing servers. For most WordPress developers, though, they’re a necessary evil we’d rather offload. We pay for hosting to avoid the hassle, but that doesn’t magically fix everything. You’re still worrying about whether your site can handle a traffic spike and often overpaying ‘just in case.’

Well, that’s what serverless WordPress aims to fix. With a serverless approach, you genuinely pay only for what you use. Meanwhile, you get an infrastructure that can go from zero traffic to handling thousands of visitors in seconds.

This talk will go over serverless WordPress and how it works. You’ll learn how it differs from regular WordPress hosting with a traditional server setup and why it’s a game-changer for demanding sites like WooCommerce and how it can transform your development workflows.

We’ll finish by sharing stories from the trenches about conquering massive traffic and cutting costs. We’ll also go over tools and projects you can use to deploy your serverless WordPress site.

Transcript

1. Serverless WordPress Demystified
2. 2 Hi! 2 I’m Carl Alexander carlalexander.ca
4. 1 Why I love Serverless
6. I wanted to write code
7. But ended up an accidental sysadmin
8. I wanted the Vercel experience
9. I wanted to ship
10. I wanted to scale
11. I wanted to sleep
12. Serverless gave me that
13. 2What Is Serverless?
14. “Are there really no servers with serverless!?” - Literally everyone I mention serverless to
16. Marketing term
17. Functions as a Service
18. On-demand computing
19. Upload code to a cloud provider
20. Code gets executed in response to an event
21. No mention of servers
22. Outside your sphere of concerns
23. 3How Does It Work?
24. WordPress on a server
26. Serverless WordPress is serverless PHP
27. How does PHP work on a web server?
29. How does serverless PHP compare?
30. Both run code in response to an event
31. So what’s different?
32. Not just PHP that runs without a server
34. PHP runtime?
35. Unique element of serverless PHP
36. What does it do?
37. Processes lambda event
38. Figures out what the event wants
39. Sends a result back (HTTP response)
40. Mimics a web server
41. Request a file, returns a file
42. Creates FastCGI request, sends it to PHP-FPM
43. Also manages the PHP-FPM process
44. Only one PHP-FPM worker
45. Lambda only handles one event at a time
46. Serverless WordPress architecture
48. ?Questions
49. 4Serverless Trade-Offs
50. No maintenance
52. No downtime
54. More secure
56. Scaling in seconds not minutes
58. Each Lambda function is a PHP worker
60. How much would scaling like that cost?
61. Pay for a server that can handle it
62. None of that with serverless
63. Usage based pricing
64. Pay when your workers run
66. Less predictable cost
67. Paying for a server feels safe
68. Need more scaling? Pay more!
70. Stressful and harder to budget for
72. Very technical solution
73. Distributed architecture
74. Latency matters!
75. Amplifies poor software practices
76. WordPress assumes you’re on a server
77. Can’t install themes and plugins directly
78. Media library
79. WordPress plugins assume it too
80. Potential compatibility issues
82. Cloud lock-in
83. Service based architecture
84. 5Evaluating Serverless
85. Tempting to only compare cost
86. “Serverless is expensive. I could just get a $5/month droplet from DigitalOcean.” - Someone comfortable with servers
87. Dishonest
88. Intangible costs
89. Mental health
90. Your time
91. ?Questions
92. 6Case Studies
93. 93 7 JOE Media Group https://joemedia.group
94. Needed to bring infra in-house
95. Deployments under 4 minutes
96. Handle scaling to 2300+ users in 60s
97. No DevOps team
98. Massive cost savings
99. Increased reliability and user retention
100. 100 7 Open House New York https://ohny.org
101. Nonprofit
102. Once a year traffic spike
103. Required enterprise hosting plan
104. Down to $8/month in the off season (~$30/month without nonprofit discounts)
105. 105 7 Anonymous Store [TOP SECRET]
106. Event-driven store
107. Eliminated outages
108. Cost reduced by 66%
109. Never slept better
110. 7Tools and Projects
112. Serverless WordPress is open source
113. github.com/ymirapp
114. 114 7 Ymir https://ymirapp.com/open
115. 8Final Thoughts
116. Customers have more expectations
117. Shouldn’t care about servers
118. Serverless lets you focus on the essential
119. 119 Thank you! 2 carlalexander.ca blog.ymirapp.com
120. ?Questions